import { InjectionToken } from '@angular/core';
import { AbstractControl } from '@angular/forms';
import { Observable } from 'rxjs';
import { ValidationAlerts } from '../validation-alert/validation-alert';
export interface SmeAsyncValidator {
    validate(c: AbstractControl): Observable<ValidationAlerts | null>;
}
/**
 * Injection token used to provide {@link SmeAsyncValidator} references
 */
export declare const SME_ASYNC_VALIDATORS: InjectionToken<SmeAsyncValidator[]>;